<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title></title>

    <meta charset="utf-8">
    <title>3D烟花</title>

    <style>
        html,body{
            margin:0px;
            width:100%;.
            height:100%;
            overflow:hidden;
            background:#000;
        }

        #canvas{
            width:100%;
            height:100%;
        }
    </style>
</head>

<body>
<canvas id="canvas" width="825" height="631"></canvas><script>
    function initVars(){

        pi=Math.PI;
        ctx=canvas.getContext("2d");
        canvas.width=canvas.clientWidth;
        canvas.height=canvas.clientHeight;
        cx=canvas.width/2;
        cy=canvas.height/2;
        playerZ=-25;
        playerX=playerY=playerVX=playerVY=playerVZ=pitch=yaw=pitchV=yawV=0;
        scale=600;
        seedTimer=0;seedInterval=5,seedLife=100;gravity=.02;
        seeds=new Array();
        sparkPics=new Array();
        s="https://cantelope.org/NYE/";
        for(i=1;i<=10;++i){
            sparkPic=new Image();
            sparkPic.src=s+"spark"+i+".png";
            sparkPics.push(sparkPic);
        }
        sparks=new Array();
        pow1=new Audio(s+"pow1.ogg");
        pow2=new Audio(s+"pow2.ogg");
        pow3=new Audio(s+"pow3.ogg");
        pow4=new Audio(s+"pow4.ogg");
        frames = 0;
    }

    function rasterizePoint(x,y,z){

        var p,d;
        x-=playerX;
        y-=playerY;
        z-=playerZ;
        p=Math.atan2(x,z);
        d=Math.sqrt(x*x+z*z);
        x=Math.sin(p-yaw)*d;
        z=Math.cos(p-yaw)*d;
        p=Math.atan2(y,z);
        d=Math.sqrt(y*y+z*z);
        y=Math.sin(p-pitch)*d;
        z=Math.cos(p-pitch)*d;
        var rx1=-1000,ry1=1,rx2=1000,ry2=1,rx3=0,ry3=0,rx4=x,ry4=z,uc=(ry4-ry3)*(rx2-rx1)-(rx4-rx3)*(ry2-ry1);
        if(!uc) return {x:0,y:0,d:-1};
        var ua=((rx4-rx3)*(ry1-ry3)-(ry4-ry3)*(rx1-rx3))/uc;
        var ub=((rx2-rx1)*(ry1-ry3)-(ry2-ry1)*(rx1-rx3))/uc;
        if(!z)z=.000000001;
        if(ua>0&&ua<1&&ub>0&&ub<1){
            return {
                x:cx+(rx1+ua*(rx2-rx1))*scale,
                y:cy+y/z*scale,
                d:Math.sqrt(x*x+y*y+z*z)
            };
        }else{
            return {
                x:cx+(rx1+ua*(rx2-rx1))*scale,
                y:cy+y/z*scale,
                d:-1
            };
        }
    }

    function spawnSeed(){

        seed=new Object();
        seed.x=-50+Math.random()*100;
        seed.y=25;
        seed.z=-50+Math.random()*100;
        seed.vx=.1-Math.random()*.2;
        seed.vy=-1.5;//*(1+Math.random()/2);
        seed.vz=.1-Math.random()*.2;
        seed.born=frames;
        seeds.push(seed);
    }

    function splode(x,y,z){

        t=5+parseInt(Math.random()*150);
        sparkV=1+Math.random()*2.5;
        type=parseInt(Math.random()*3);
        switch(type){
            case 0:
                pic1=parseInt(Math.random()*10);
                break;
            case 1:
                pic1=parseInt(Math.random()*10);
                do{ pic2=parseInt(Math.random()*10); }while(pic2==pic1);
                break;
            case 2:
                pic1=parseInt(Math.random()*10);
                do{ pic2=parseInt(Math.random()*10); }while(pic2==pic1);
                do{ pic3=parseInt(Math.random()*10); }while(pic3==pic1 || pic3==pic2);
                break;
        }
        for(m=1;m<t;++m){
            spark=new Object();
            spark.x=x; spark.y=y; spark.z=z;
            p1=pi*2*Math.random();
            p2=pi*Math.random();
            v=sparkV*(1+Math.random()/6)
            spark.vx=Math.sin(p1)*Math.sin(p2)*v;
            spark.vz=Math.cos(p1)*Math.sin(p2)*v;
            spark.vy=Math.cos(p2)*v;
            switch(type){
                case 0: spark.img=sparkPics[pic1]; break;
                case 1:
                    spark.img=sparkPics[parseInt(Math.random()*2)?pic1:pic2];
                    break;
                case 2:
                    switch(parseInt(Math.random()*3)){
                        case 0: spark.img=sparkPics[pic1]; break;
                        case 1: spark.img=sparkPics[pic2]; break;
                        case 2: spark.img=sparkPics[pic3]; break;
                    }
                    break;
            }
            spark.radius=25+Math.random()*50;
            spark.alpha=1;
            spark.trail=new Array();
            sparks.push(spark);
        }
        switch(parseInt(Math.random()*4)){
            case 0: pow=new Audio(s+"pow1.ogg"); break;
            case 1: pow=new Audio(s+"pow2.ogg"); break;
            case 2: pow=new Audio(s+"pow3.ogg"); break;
            case 3: pow=new Audio(s+"pow4.ogg"); break;
        }
        d=Math.sqrt((x-playerX)*(x-playerX)+(y-playerY)*(y-playerY)+(z-playerZ)*(z-playerZ));
        pow.volume=1.5/(1+d/10);
        pow.play();
    }

    function doLogic(){

        if(seedTimer<frames){
            seedTimer=frames+seedInterval*Math.random()*10;
            spawnSeed();
        }
        for(i=0;i<seeds.length;++i){
            seeds[i].vy+=gravity;
            seeds[i].x+=seeds[i].vx;
            seeds[i].y+=seeds[i].vy;
            seeds[i].z+=seeds[i].vz;
            if(frames-seeds[i].born>seedLife){
                splode(seeds[i].x,seeds[i].y,seeds[i].z);
                seeds.splice(i,1);
            }
        }
        for(i=0;i<sparks.length;++i){
            if(sparks[i].alpha>0 && sparks[i].radius>5){
                sparks[i].alpha-=.01;
                sparks[i].radius/=1.02;
                sparks[i].vy+=gravity;
                point=new Object();
                point.x=sparks[i].x;
                point.y=sparks[i].y;
                point.z=sparks[i].z;
                if(sparks[i].trail.length){
                    x=sparks[i].trail[sparks[i].trail.length-1].x;
                    y=sparks[i].trail[sparks[i].trail.length-1].y;
                    z=sparks[i].trail[sparks[i].trail.length-1].z;
                    d=((point.x-x)*(point.x-x)+(point.y-y)*(point.y-y)+(point.z-z)*(point.z-z));
                    if(d>9){
                        sparks[i].trail.push(point);
                    }
                }else{
                    sparks[i].trail.push(point);
                }
                if(sparks[i].trail.length>5)sparks[i].trail.splice(0,1);
                sparks[i].x+=sparks[i].vx;
                sparks[i].y+=sparks[i].vy;
                sparks[i].z+=sparks[i].vz;
                sparks[i].vx/=1.075;
                sparks[i].vy/=1.075;
                sparks[i].vz/=1.075;
            }else{
                sparks.splice(i,1);
            }
        }
        p=Math.atan2(playerX,playerZ);
        d=Math.sqrt(playerX*playerX+playerZ*playerZ);
        d+=Math.sin(frames/80)/1.25;
        t=Math.sin(frames/200)/40;
        playerX=Math.sin(p+t)*d;
        playerZ=Math.cos(p+t)*d;
        yaw=pi+p+t;
    }

    function rgb(col){

        var r = parseInt((.5+Math.sin(col)*.5)*16);
        var g = parseInt((.5+Math.cos(col)*.5)*16);
        var b = parseInt((.5-Math.sin(col)*.5)*16);
        return "#"+r.toString(16)+g.toString(16)+b.toString(16);
    }

    function draw(){

        ctx.clearRect(0,0,cx*2,cy*2);

        ctx.fillStyle="#ff8";
        for(i=-100;i<100;i+=3){
            for(j=-100;j<100;j+=4){
                x=i;z=j;y=25;
                point=rasterizePoint(x,y,z);
                if(point.d!=-1){
                    size=250/(1+point.d);
                    d = Math.sqrt(x * x + z * z);
                    a = 0.75 - Math.pow(d / 100, 6) * 0.75;
                    if(a>0){
                        ctx.globalAlpha = a;
                        ctx.fillRect(point.x-size/2,point.y-size/2,size,size);
                    }
                }
            }
        }
        ctx.globalAlpha=1;
        for(i=0;i<seeds.length;++i){
            point=rasterizePoint(seeds[i].x,seeds[i].y,seeds[i].z);
            if(point.d!=-1){
                size=200/(1+point.d);
                ctx.fillRect(point.x-size/2,point.y-size/2,size,size);
            }
        }
        point1=new Object();
        for(i=0;i<sparks.length;++i){
            point=rasterizePoint(sparks[i].x,sparks[i].y,sparks[i].z);
            if(point.d!=-1){
                size=sparks[i].radius*200/(1+point.d);
                if(sparks[i].alpha<0)sparks[i].alpha=0;
                if(sparks[i].trail.length){
                    point1.x=point.x;
                    point1.y=point.y;
                    switch(sparks[i].img){
                        case sparkPics[0]:ctx.strokeStyle="#f84";break;
                        case sparkPics[1]:ctx.strokeStyle="#84f";break;
                        case sparkPics[2]:ctx.strokeStyle="#8ff";break;
                        case sparkPics[3]:ctx.strokeStyle="#fff";break;
                        case sparkPics[4]:ctx.strokeStyle="#4f8";break;
                        case sparkPics[5]:ctx.strokeStyle="#f44";break;
                        case sparkPics[6]:ctx.strokeStyle="#f84";break;
                        case sparkPics[7]:ctx.strokeStyle="#84f";break;
                        case sparkPics[8]:ctx.strokeStyle="#fff";break;
                        case sparkPics[9]:ctx.strokeStyle="#44f";break;
                    }
                    for(j=sparks[i].trail.length-1;j>=0;--j){
                        point2=rasterizePoint(sparks[i].trail[j].x,sparks[i].trail[j].y,sparks[i].trail[j].z);
                        if(point2.d!=-1){
                            ctx.globalAlpha=j/sparks[i].trail.length*sparks[i].alpha/2;
                            ctx.beginPath();
                            ctx.moveTo(point1.x,point1.y);
                            ctx.lineWidth=1+sparks[i].radius*10/(sparks[i].trail.length-j)/(1+point2.d);
                            ctx.lineTo(point2.x,point2.y);
                            ctx.stroke();
                            point1.x=point2.x;
                            point1.y=point2.y;
                        }
                    }
                }
                ctx.globalAlpha=sparks[i].alpha;
                ctx.drawImage(sparks[i].img,point.x-size/2,point.y-size/2,size,size);
            }
        }
    }

    function frame(){

        if(frames>100000){
            seedTimer=0;
            frames=0;
        }
        frames++;
        draw();
        doLogic();
        requestAnimationFrame(frame);
    }

    window.addEventListener("resize",()=>{
        canvas.width=canvas.clientWidth;
        canvas.height=canvas.clientHeight;
        cx=canvas.width/2;
        cy=canvas.height/2;
    });

    initVars();
    frame();</script>


</body>
</html>